win_qextserialport.cpp

在linux下的QT中使用串口的编程方法

/*!
\class Win_QextSerialPort
\version 1.0.0
\author Stefan Sander

A cross-platform serial port class.
This class encapsulates the Windows portion of QextSerialPort.  The user will be notified of
errors and possible portability conflicts at run-time by default - this behavior can be turned
off by defining _TTY_NOWARN_ (to turn off all warnings) or _TTY_NOWARN_PORT_ (to turn off
portability warnings) in the project.  Note that defining _TTY_NOWARN_ also defines
_TTY_NOWARN_PORT_.

\note
On Windows NT/2000/XP this class uses Win32 serial port functions by default.  The user may
select POSIX behavior under NT, 2000, or XP ONLY by defining _TTY_POSIX_ in the project. I can
make no guarantees as to the quality of POSIX support under NT/2000 however.

*/

#include <stdio.h>
#include "win_qextserialport.h"

/*!
\fn Win_QextSerialPort::Win_QextSerialPort()
Default constructor.  Note that the name of the device used by a Win_QextSerialPort constructed
with this constructor will be determined by #defined constants, or lack thereof - the default
behavior is the same as _TTY_LINUX_.  Possible naming conventions and their associated constants
are:

\verbatim

Constant         Used By         Naming Convention
----------       -------------   ------------------------
_TTY_WIN_        Windows         COM1, COM2
_TTY_IRIX_       SGI/IRIX        /dev/ttyf1, /dev/ttyf2
_TTY_HPUX_       HP-UX           /dev/tty1p0, /dev/tty2p0
_TTY_SUN_        SunOS/Solaris   /dev/ttya, /dev/ttyb
_TTY_DIGITAL_    Digital UNIX    /dev/tty01, /dev/tty02
_TTY_FREEBSD_    FreeBSD         /dev/ttyd0, /dev/ttyd1
_TTY_LINUX_      Linux           /dev/ttyS0, /dev/ttyS1
<none>           Linux           /dev/ttyS0, /dev/ttyS1
\endverbatim

This constructor associates the object with the first port on the system, e.g. COM1 for Windows
platforms.  See the other constructor if you need a port other than the first.
*/
Win_QextSerialPort::Win_QextSerialPort():QextSerialBase() {
    Win_Handle=INVALID_HANDLE_VALUE;
}

/*!Win_QextSerialPort::Win_QextSerialPort(const Win_QextSerialPort&)
Copy constructor.
*/
Win_QextSerialPort::Win_QextSerialPort(const Win_QextSerialPort& s):QextSerialBase(s.port) {
    Win_Handle=INVALID_HANDLE_VALUE;
    setOpenMode(s.openMode());
    lastErr=s.lastErr;
    port = s.port;
    Settings.FlowControl=s.Settings.FlowControl;
    Settings.Parity=s.Settings.Parity;
    Settings.DataBits=s.Settings.DataBits;
    Settings.StopBits=s.Settings.StopBits;
    Settings.BaudRate=s.Settings.BaudRate;
    Win_Handle=s.Win_Handle;
    memcpy(&Win_CommConfig, &s.Win_CommConfig, sizeof(COMMCONFIG));
    memcpy(&Win_CommTimeouts, &s.Win_CommTimeouts, sizeof(COMMTIMEOUTS));
}

/*!
\fn Win_QextSerialPort::Win_QextSerialPort(const QString & name)
Constructs a serial port attached to the port specified by devName.
devName is the name of the device, which is windowsystem-specific,
e.g."COM2" or "/dev/ttyS0".
*/
Win_QextSerialPort::Win_QextSerialPort(const QString & name):QextSerialBase(name) {
    Win_Handle=INVALID_HANDLE_VALUE;
}

/*!
\fn Win_QextSerialPort::Win_QextSerialPort(const PortSettings& settings)
Constructs a port with default name and specified settings.
*/
Win_QextSerialPort::Win_QextSerialPort(const PortSettings& settings) {
    Win_Handle=INVALID_HANDLE_VALUE;
    setBaudRate(settings.BaudRate);
    setDataBits(settings.DataBits);
    setStopBits(settings.StopBits);
    setParity(settings.Parity);
    setFlowControl(settings.FlowControl);
    setTimeout(settings.Timeout_Sec, settings.Timeout_Millisec);
}

/*!
\fn Win_QextSerialPort::Win_QextSerialPort(const QString & name, const PortSettings& settings)
Constructs a port with specified name and settings.
*/
Win_QextSerialPort::Win_QextSerialPort(const QString & name, const PortSettings& settings) {
    Win_Handle=INVALID_HANDLE_VALUE;
    setPortName(name);
    setBaudRate(settings.BaudRate);
    setDataBits(settings.DataBits);
    setStopBits(settings.StopBits);
    setParity(settings.Parity);
    setFlowControl(settings.FlowControl);
    setTimeout(settings.Timeout_Sec, settings.Timeout_Millisec);
}

/*!
\fn Win_QextSerialPort::~Win_QextSerialPort()
Standard destructor.
*/
Win_QextSerialPort::~Win_QextSerialPort() {
    if (isOpen()) {
        close();
    }
}

/*!
\fn Win_QextSerialPort& Win_QextSerialPort::operator=(const Win_QextSerialPort& s)
overrides the = operator
*/
Win_QextSerialPort& Win_QextSerialPort::operator=(const Win_QextSerialPort& s) {
    setOpenMode(s.openMode());
    lastErr=s.lastErr;
    port = s.port;
    Settings.FlowControl=s.Settings.FlowControl;
    Settings.Parity=s.Settings.Parity;
    Settings.DataBits=s.Settings.DataBits;
    Settings.StopBits=s.Settings.StopBits;
    Settings.BaudRate=s.Settings.BaudRate;
    Win_Handle=s.Win_Handle;
    memcpy(&Win_CommConfig, &s.Win_CommConfig, sizeof(COMMCONFIG));
    memcpy(&Win_CommTimeouts, &s.Win_CommTimeouts, sizeof(COMMTIMEOUTS));
    return *this;
}

/*!
\fn bool Win_QextSerialPort::open(OpenMode mode)
Opens a serial port.  Note that this function does not specify which device to open.  If you need
to open a device by name, see Win_QextSerialPort::open(const char*).  This function has no effect
if the port associated with the class is already open.  The port is also configured to the current
settings, as stored in the Settings structure.
*/
bool Win_QextSerialPort::open(OpenMode mode) {
    unsigned long confSize = sizeof(COMMCONFIG);
    Win_CommConfig.dwSize = confSize;

    LOCK_MUTEX();
    if (mode == QIODevice::NotOpen)
        return isOpen();
    if (!isOpen()) {
        /*open the port*/
        Win_Handle=CreateFileA(port.toAscii(), GENERIC_READ|GENERIC_WRITE,
                              FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
        if (Win_Handle!=INVALID_HANDLE_VALUE) {
            /*set open mode*/
            QIODevice::open(mode);

            /*configure port settings*/
            GetCommConfig(Win_Handle, &Win_CommConfig, &confSize);
            GetCommState(Win_Handle, &(Win_CommConfig.dcb));

            /*set up parameters*/
            Win_CommConfig.dcb.fBinary=TRUE;
            Win_CommConfig.dcb.fInX=FALSE;
            Win_CommConfig.dcb.fOutX=FALSE;
            Win_CommConfig.dcb.fAbortOnError=FALSE;
            Win_CommConfig.dcb.fNull=FALSE;
            setBaudRate(Settings.BaudRate);
            setDataBits(Settings.DataBits);
            setStopBits(Settings.StopBits);
            setParity(Settings.Parity);
            setFlowControl(Settings.FlowControl);
            setTimeout(Settings.Timeout_Sec, Settings.Timeout_Millisec);
            SetCommConfig(Win_Handle, &Win_CommConfig, sizeof(COMMCONFIG));
        }
    }
    UNLOCK_MUTEX();
    return isOpen();
}

/*!
\fn void Win_QextSerialPort::close()
Closes a serial port.  This function has no effect if the serial port associated with the class
is not currently open.
*/
void Win_QextSerialPort::close() {
    LOCK_MUTEX();
    CloseHandle(Win_Handle);
    QIODevice::close();
    UNLOCK_MUTEX();
}

/*!
\fn void Win_QextSerialPort::flush()
Flushes all pending I/O to the serial port.  This function has no effect if the serial port
associated with the class is not currently open.
*/
void Win_QextSerialPort::flush() {
    LOCK_MUTEX();
    if (isOpen()) {
        FlushFileBuffers(Win_Handle);
    }
    UNLOCK_MUTEX();
}

/*!
\fn qint64 Win_QextSerialPort::size() const
This function will return the number of bytes waiting in the receive queue of the serial port.
It is included primarily to provide a complete QIODevice interface, and will not record errors
in the lastErr member (because it is const).  This function is also not thread-safe - in
multithreading situations, use Win_QextSerialPort::bytesAvailable() instead.
*/
qint64 Win_QextSerialPort::size() const {
    int availBytes;
    COMSTAT Win_ComStat;
    DWORD Win_ErrorMask=0;
    ClearCommError(Win_Handle, &Win_ErrorMask, &Win_ComStat);
    availBytes = Win_ComStat.cbInQue;
    return (qint64)availBytes;
}

/*!
\fn qint64 Win_QextSerialPort::bytesAvailable()
Returns the number of bytes waiting in the port's receive queue.  This function will return 0 if
the port is not currently open, or -1 on error.  Error information can be retrieved by calling
Win_QextSerialPort::getLastError().
*/
qint64 Win_QextSerialPort::bytesAvailable() {
    LOCK_MUTEX();
    if (isOpen()) {
        DWORD Errors;
        COMSTAT Status;
        bool success=ClearCommError(Win_Handle, &Errors, &Status);
        translateError(Errors);
        if (success) {
            lastErr=E_NO_ERROR;
            UNLOCK_MUTEX();
            return Status.cbInQue + QIODevice::bytesAvailable();
        }
        UNLOCK_MUTEX();
        return (unsigned int)-1;
    }
    UNLOCK_MUTEX();
    return 0;
}

/*!
\fn void Win_QextSerialPort::translateError(ulong error)
Translates a system-specific error code to a QextSerialPort error code.  Used internally.
*/
void Win_QextSerialPort::translateError(ulong error) {
    if (error&CE_BREAK) {
        lastErr=E_BREAK_CONDITION;
    }
    else if (error&CE_FRAME) {
        lastErr=E_FRAMING_ERROR;
    }
    else if (error&CE_IOE) {
        lastErr=E_IO_ERROR;
    }
    else if (error&CE_MODE) {
        lastErr=E_INVALID_FD;
    }
    else if (error&CE_OVERRUN) {
        lastErr=E_BUFFER_OVERRUN;
    }
    else if (error&CE_RXPARITY) {
        lastErr=E_RECEIVE_PARITY_ERROR;
    }
    else if (error&CE_RXOVER) {
        lastErr=E_RECEIVE_OVERFLOW;
    }
    else if (error&CE_TXFULL) {
        lastErr=E_TRANSMIT_OVERFLOW;
    }
}

/*!
\fn qint64 Win_QextSerialPort::readData(char *data, qint64 maxSize)
Reads a block of data from the serial port.  This function will read at most maxlen bytes from
the serial port and place them in the buffer pointed to by data.  Return value is the number of
bytes actually read, or -1 on error.

\warning before calling this function ensure that serial port associated with this class
is currently open (use isOpen() function to check if port is open).
*/
qint64 Win_QextSerialPort::readData(char *data, qint64 maxSize)
{
    LOCK_MUTEX();
    int retVal=0;
    COMSTAT Win_ComStat;
    DWORD Win_BytesRead=0;
    DWORD Win_ErrorMask=0;
    ClearCommError(Win_Handle, &Win_ErrorMask, &Win_ComStat);
    if (Win_ComStat.cbInQue &&
        (!ReadFile(Win_Handle, (void*)data, (DWORD)maxSize, &Win_BytesRead, NULL)
        || Win_BytesRead==0)) {
        lastErr=E_READ_FAILED;
        retVal=-1;
    }
    else {
        retVal=((int)Win_BytesRead);
    }
    UNLOCK_MUTEX();

    return retVal;
}

/*!
\fn qint64 Win_QextSerialPort::writeData(const char *data, qint64 maxSize)
Writes a block of data to the serial port.  This function will write len bytes
from the buffer pointed to by data to the serial port.  Return value is the number
of bytes actually written, or -1 on error.

\warning before calling this function ensure that serial port associated with this class
is currently open (use isOpen() function to check if port is open).
*/
qint64 Win_QextSerialPort::writeData(const char *data, qint64 maxSize)
{
    LOCK_MUTEX();
    int retVal=0;
    DWORD Win_BytesWritten;
    if (!WriteFile(Win_Handle, (void*)data, (DWORD)maxSize, &Win_BytesWritten, NULL)) {
        lastErr=E_WRITE_FAILED;
        retVal=-1;
    }
    else {
        retVal=((int)Win_BytesWritten);
    }
    UNLOCK_MUTEX();

    flush();
    return retVal;
}

/*!
\fn void Win_QextSerialPort::ungetChar(char c)
This function is included to implement the full QIODevice interface, and currently has no
purpose within this class.  This function is meaningless on an unbuffered device and currently
only prints a warning message to that effect.
*/
void Win_QextSerialPort::ungetChar(char c) {

    /*meaningless on unbuffered sequential device - return error and print a warning*/
    TTY_WARNING("Win_QextSerialPort: ungetChar() called on an unbuffered sequential device - operation is meaningless");
}

/*!
\fn void Win_QextSerialPort::setFlowControl(FlowType flow)
Sets the flow control used by the port.  Possible values of flow are:
\verbatim
    FLOW_OFF            No flow control
    FLOW_HARDWARE       Hardware (RTS/CTS) flow control
    FLOW_XONXOFF        Software (XON/XOFF) flow control
\endverbatim
*/
void Win_QextSerialPort::setFlowControl(FlowType flow) {
    LOCK_MUTEX();
    if (Settings.FlowControl!=flow) {
        Settings.FlowControl=flow;
    }
    if (isOpen()) {
        switch(flow) {

            /*no flow control*/
            case FLOW_OFF:
                Win_CommConfig.dcb.fOutxCtsFlow=FALSE;
                Win_CommConfig.dcb.fRtsControl=RTS_CONTROL_DISABLE;
                Win_CommConfig.dcb.fInX=FALSE;
                Win_CommConfig.dcb.fOutX=FALSE;
                SetCommConfig(Win_Handle, &Win_CommConfig, sizeof(COMMCONFIG));
                break;

            /*software (XON/XOFF) flow control*/
            case FLOW_XONXOFF:
                Win_CommConfig.dcb.fOutxCtsFlow=FALSE;
                Win_CommConfig.dcb.fRtsControl=RTS_CONTROL_DISABLE;
                Win_CommConfig.dcb.fInX=TRUE;
                Win_CommConfig.dcb.fOutX=TRUE;
                SetCommConfig(Win_Handle, &Win_CommConfig, sizeof(COMMCONFIG));
                break;

            case FLOW_HARDWARE:
                Win_CommConfig.dcb.fOutxCtsFlow=TRUE;
                Win_CommConfig.dcb.fRtsControl=RTS_CONTROL_HANDSHAKE;
                Win_CommConfig.dcb.fInX=FALSE;
                Win_CommConfig.dcb.fOutX=FALSE;
                SetCommConfig(Win_Handle, &Win_CommConfig, sizeof(COMMCONFIG));
                break;
        }
    }
    UNLOCK_MUTEX();
}

/*!
\fn void Win_QextSerialPort::setParity(ParityType parity)
Sets the parity associated with the serial port.  The possible values of parity are:
\verbatim
    PAR_SPACE       Space Parity
    PAR_MARK        Mark Parity
    PAR_NONE        No Parity
    PAR_EVEN        Even Parity
    PAR_ODD         Odd Parity
\endverbatim
*/
void Win_QextSerialPort::setParity(ParityType parity) {
    LOCK_MUTEX();
    if (Settings.Parity!=parity) {
        Settings.Parity=parity;
    }
    if (isOpen()) {
        Win_CommConfig.dcb.Parity=(unsigned char)parity;
        switch (parity) {

            /*space parity*/
            case PAR_SPACE:
                if (Settings.DataBits==DATA_8) {
                    TTY_PORTABILITY_WARNING("Win_QextSerialPort Portability Warning: Space parity with 8 data bits is not supported by POSIX systems.");
                }
                Win_CommConfig.dcb.fParity=TRUE;
                break;

            /*mark parity - WINDOWS ONLY*/
            case PAR_MARK:
                TTY_PORTABILITY_WARNING("Win_QextSerialPort Portability Warning:  Mark parity is not supported by POSIX systems");
                Win_CommConfig.dcb.fParity=TRUE;
                break;

            /*no parity*/
            case PAR_NONE:
                Win_CommConfig.dcb.fParity=FALSE;
                break;

            /*even parity*/
            case PAR_EVEN:
                Win_CommConfig.dcb.fParity=TRUE;
                break;